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The mammalian phallus arises from identical primordia in both sexes and is patterned in part by the key morphogen Sonic hedgehog (SHH). We have investigated SHH and other morphogens during phallus development in the tammar wallaby. In this marsupial, testis differentiation and androgen production occurs just after birth, but it takes a further 50-60 days before the phallus becomes sexually dimorphic. One day before birth, SHH was expressed in both sexes in the urethral epithelium. In males, there was a marked upregulation of SHH, GLI2, and AR at day 50 postpartum, a time when testicular androgen production falls. SHH, GLI2, and AR were downregulated in female pouch young treated with androstanediol from days 24-50, but not when treatments were begun at day 29, suggesting an early window of androgen sensitivity. SHH, GLI2, and AR expression in the phallus of males castrated at day 23 did not differ from controls, but there was an increase in SHH and GLI2 and a decrease in FGF8 and BMP4 expression when the animals were castrated at day 29. These results suggest that the early patterning by SHH is androgen-independent followed by an androgen-dependent window of sensitivity and a sharp rise in SHH expression after androgen withdrawal at day 50., (© 2014 S. Karger AG, Basel.)

The Burns Centre at the Singapore General Hospital (SGH) serves as a tertiary referral centre for burns management for Singapore's 4 million residents as well as the Southeast Asia region. Our study is a multivariate analysis of all burns patients admitted between 2003 and 2005. A total of 482 patients were admitted during this period with an average annual admission of 161. This represents a low incidence of 0.04 per 1000 admissions for the Singapore population. 13.3% of the study population were children, which is lower than previous studies. The mean age at admission was 35 years old and the male:female ratio was 1.9:1. We found a significant difference in age between the local and foreign patients, with the latter being younger. Our study demonstrated a 7.3% increase in cases of occupational burns. The bulk of our patients (57.3%) were directly admitted from SGH's Accident and Emergency Department. The patient characteristics of the various referral sources were found to be very different. GP referrals had significantly lower TBSA while overseas patients had significantly higher TBSA and longer length of stay. The mean and median time to admission was 3.05 days (+/-6.26) and 0 (0-60) day, respectively and the mean and median time to surgery was 7.33 days (+/-8.18) and 5 (0-22) days, respectively. The most common cause of burns was due to scalding. The mean extent of burn (TBSA) was 13.5% (+/-18.0), with significant correlation with the social background. Length of stay was dependent on the need for surgery. The overall mortality rate in this study population was 4.5%, with inhalation injury the main aetiological factor. In addition, the mean duration of the first surgery that patients undergo was significantly longer than that of the second one. This information will be useful for estimating operation times in the future. Finally, Acinetobacter baumannii was the most common bacteria in wound cultures. There is a need for periodic reviews of wound cultures in burns patients in order to modify the preventive and therapeutic strategies against these bacteria.